iOS开发实现随机图片验证码封装

  _testView = [[NNValidationView alloc] initWithFrame:CGRectMake((self.view.frame.size.width - 100) / 2, 200, 100, 40) andCharCount:4 andLineCount:4];  [self.view addSubview:_testView];

 __weak typeof(self) weakSelf = self;  /// 返回验证码数字  _testView.changeValidationCodeBlock = ^(void){    NSLog(@"验证码被点击了：%@", weakSelf.testView.charString);  };

#pragma mark - 绘制界面- (void)drawRect:(CGRect)rect {  [super drawRect:rect];  self.backgroundColor = NNRandomColor;  CGFloat rectWidth = rect.size.width;  CGFloat rectHeight = rect.size.height;  CGFloat pointX, pointY;    NSString *text = [NSString stringWithFormat:@"%@",self.charString];  NSInteger charWidth = rectWidth / text.length - 15;  NSInteger charHeight = rectHeight - 25;    // 依次绘制文字  for (NSInteger i = 0; i < text.length; i++) {    // 文字X坐标    pointX = arc4random() % charWidth + rectWidth / text.length * i;    // 文字Y坐标    pointY = arc4random() % charHeight;    unichar charC = [text characterAtIndex:i];    NSString *textC = [NSString stringWithFormat:@"%C", charC];    [textC drawAtPoint:CGPointMake(pointX, pointY) withAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:arc4random() % 10 + 15]}];  }    // 获取上下文  CGContextRef context = UIGraphicsGetCurrentContext();  // 设置线宽  CGContextSetLineWidth(context, 1.0);    // 依次绘制直线  for(NSInteger i = 0; i < self.lineCount; i++) {    // 设置线的颜色    CGContextSetStrokeColorWithColor(context, NNRandomColor.CGColor);    // 设置线的起点    pointX = arc4random() % (NSInteger)rectWidth;    pointY = arc4random() % (NSInteger)rectHeight;    CGContextMoveToPoint(context, pointX, pointY);    // 设置线的终点    pointX = arc4random() % (NSInteger)rectWidth;    pointY = arc4random() % (NSInteger)rectHeight;    CGContextAddLineToPoint(context, pointX, pointY);    // 绘画路径    CGContextStrokePath(context);  }}